I've had my Prius since the middle of October 2005. I've noticed that the engine sometimes diesels or shudders as it is turning itself off either as I'm stopped or slowing. Is this something to worry about/get fixed?
Nothing to worry about, nothing to get fixed. Becomes less frequent in time and when the ICE is completely warmed up.
Tends to be a cold weather condition but can happen any time. The ICE shutters when shutting down. Check out the Knowledge Base looking for Stages of Hybrid Operation, Stage II is said to be a bit stubborn. The details are not fixed in stone but it is a starting point. At any rate is a known condition.
